Footage posted online yesterday shows thousands of spiders "falling from the sky" in the southern Brazilian town of Santo Antônio da Platina.

"Still do not know what causes such behavior," writes the video's uploader. "We are researching and will post the answer to the question here."

I know exactly what causes such behavior. A little something called the end of the world.

UPDATE: Brazilian news portal G1 reports that this footage was captured by 20-year-old web designer Erick Reis as he was leaving a friend's engagement party this past Sunday.

G1 spoke with a local biologist who identified the spider as Anelosimus eximius — a "social spider" species known for its massive colonies and "sheet webs." He characterized the phenomenon as "normal," which it most certainly is not.